Hotels in Soi 11 are where I usually stay. Most are fairly ok. Mercur hotel has a nice restaurant but what it distinguishes for me, is the value you get. I upgraded my room with Lounge access. It was great. The folks in the privilege lounge are very helpful and attentive. My room was on the same floor which was extremely convenient. I could simply ask anything I want from the staff in the lounge and it would be taken care of. The front lobby is well maintained and clean and staff fairly attentive and with good attitude. I have eaten breakfast there and the buffet is fairly good.
Location is perfect if you are into nightlife, close to Nana, and BTS , very convenient with many super nice restaurants and superb bar scene within walking outside the hotel.
Of course, price is a little higher than what you expect from Thailand, but you are really paying for the close proximity to the nightlife and convenience.
Hotel has a nice pool also for chilling out.
Aire acondicionado